Quote Originally Posted by Throbert McGee View Post
For #1 -- Yes, you can say африканцы со СПИДом (Africans with AIDS), for example.

For #2 and #3 -- if you don't want to use an infinitive, as Seraph suggested, my gut instinct is that you could use по + dative or possibly о + prepositional, depending on the context.

For example, Я им помогаю по английской грамматике, "I am helping them with English grammar." (Compare with constructions like: Студенты сдают экзамен по биологии, "The students are taking an exam in biology.")

And with Google, I find that you can definitely say things like соревнование по плаванию ("a swimming competition"), as well as тренер по плаванию ("swimming instructor").

However, I would get a second opinion from a native speaker!
Всё правильно. Можно также сказать : Я им помогаю с английской грамматикой или помогаю разобраться в английской грамматике.